A couple of things worth noting.
1. Typical soldiers, regulars, sergeants at arms, cavalry troops that sort of thing typically wore at most the base color of their lord and his badge typically on the left chest though that is not by any stretch a hard and fast rule there was a great deal of variation.
2. Heraldry changed a lot over the years in general terms from simpler to more complex. If you want accuracy it's a good idea to research the heraldry from the time that you're after.
3. Heraldry is a science not an art the colors and meanings are specific again if you want accuracy it pays to do some research.
Cheers,
JiB